How to transfer the whole balance of an account?

Question

If I have an account with 5 ETH, can I send the full account balance of 5ETH to another account and have exactly 5ETH received on the second account ?

I understood that it will fail because I have no ether left to pay for the transaction fees.

If I want exactly 5 ETH to be received by the second account, I think I should have around 5,0002 ETH in my account to be able to transfer 5 ETH. Can you confirm?

Answer 1

No.

You cannot send the entire balance because the fees are deducted from your account's balance, not from the value being sent. To sweep an account you need to send balance-gas*price ETH as the value, and also manually set the gas and gasPrice to ensure that you exactly zero your account.

E.g. If you have 5ETH and want to sweep it:

• A plain account-to-account transaction costs 21000 gas
• The current minimum gas price in the network is 20 GWei
• Set value to 5ETH - 21000*20GWei = 5ETH - 42K GWei = 4.999958ETH

Answer 2

Basic answer is no !

Anytime you want to perform a transaction, you'll have to pay a fee for the computation involved in validating and mining your tx. If you do not have enough gas, you cannot send your tx to the network. In your example, send "all" and the receiver will get 5 minus fees.

Answer 3

My suggestion would be to automate it.

First, set the account and unlock it after launching geth attach:

var accountNum = 0
personal.unlockAccount(eth.accounts[accountNum]);

Now

var amount_to_send_eth = web3.fromWei(eth.getBalance(eth.accounts[accountNum]), "ether");
var amount_to_send_wei = amount_to_send_eth *1000000000000000000
var transactionFee = web3.eth.gasPrice * 21001;
var total_amount_to_send_wei = transactionFee + amount_to_send_wei 
eth.sendTransaction({from:eth.accounts[accountNum], to:"0xD3ADB33FD3ADB33FD3ADB33F", value: total_amount_to_send_wei });

After that, a TXID is returned, that can be used to check if the transaction completed.

I'm a beginner, so hints how to imrpove it further are appreciated!

Answer 4

If you are using blockcypher simply send -1 as the amount.

Answer 5

var transferAll = function(from, to) {
  var gas = '30000';
  var gasPrice = eth.gasPrice;
  var gasTotal = gasPrice.mul(gas);
  var totalValue = eth.getBalance(from).sub(gasTotal)-1;
  console.log("Transfer :"+totalValue+", from "+from+" to "+to);
  personal.unlockAccount(from);
  var result = eth.sendTransaction({from: from, to: to, value: totalValue});
  console.log("Transaction hash:", result);
};